A control method, device, system and equipment for free-fall type auxiliary agent dropping

Abstract

The application provides a free-fall auxiliary agent drop control method, device, system and equipment, and belongs to the technical field of fine chemical process control. The control method comprises the following steps: obtaining target drop parameters and the initial weight of a drop tank, wherein the target drop parameters comprise a target total drop amount and a drop time; calculating an adjusting valve opening value by using the target drop parameters and the initial weight according to a preset quantitative calculation model, wherein the model represents the quantitative relationship between the initial weight, the valve opening and the drop speed; controlling the adjusting valve to perform initial loading based on the opening value to start the drop; and switching between a time uniform speed mode and a weight deviation compensation mode according to a preset condition to control the adjusting valve during the drop, wherein the former uniformly drops at a target flow rate, and the latter dynamically adjusts the target flow rate and corrects the valve opening based on the real-time drop amount deviation. The quantitative model is used to realize accurate initial opening calculation, and the double-mode switching control is combined to improve the control accuracy, stability and time controllability of the drop process.

Description

Technical Field

[0001] This application relates to the field of fine chemical process control technology, specifically to a control method, device, system and equipment for free-fall type additive dripping. Background Technology

[0002] In fine chemical production, the dropwise addition of various additives, such as emulsifiers, initiators, and modifiers, is a core process in product synthesis. Some additives, due to their poor thermal stability and susceptibility to shear damage, cannot be pumped and must be added via free-fall dropwise, relying on gravity to achieve slow and stable addition. As the fine chemical industry continues to demand higher product quality, the requirements for the timing, quantity, uniformity, and stability of additive dropwise addition are becoming increasingly stringent.

[0003] Currently, the industry commonly employs a control method based on manual or simple automatic adjustment of regulating valves, combined with weighing feedback. Specifically, operators set the initial opening of the regulating valve based on experience, and during the dripping process, adjust the valve opening manually or using a simple closed-loop control algorithm (such as PID control) based on the deviation between the flow rate calculated from real-time weighing data and the target value. However, during free-fall dripping, the relationship between the actual valve opening and the material flow rate is influenced by multiple factors such as the initial weight of the dripping tank and changes in liquid level, exhibiting complex, nonlinear, and time-varying characteristics. The aforementioned adjustment method, relying on real-time deviation feedback, struggles to accurately characterize and adapt to this complex dynamic relationship, resulting in valve adjustment lag and difficulty in ensuring the uniformity and stability of the dripping process. Furthermore, the setting of the initial valve opening lacks theoretical basis and relies entirely on operational experience, easily leading to uncontrolled or unstable flow rates during the start-up phase. Summary of the Invention

[0004] In view of this, this application aims to provide a control method, device, system and equipment for free-fall additive dripping, in order to solve the problem of how to overcome the nonlinear time-varying coupling relationship between valve opening and flow rate in the existing free-fall dripping control of fine chemicals, and to achieve fast, accurate and stable valve control without relying on operating experience.

[0005] A first aspect of the present invention provides a control method for free-fall additive dripping, applied to a control system, the method comprising: Obtain the target dropping parameters and the initial weight of the dropping tank; the dropping tank is used to store the additives, and a regulating valve is installed on the discharge pipe of the dropping tank. The target dropping parameters include the target total dropping volume and the target dropping time. Based on the quantitative calculation model pre-installed in the control system, the opening value of the regulating valve is calculated using the target dripping parameters and the initial weight. The quantitative calculation model characterizes the coupling influence relationship between the initial weight, the opening of the regulating valve, and the dripping speed. The control valve is adjusted based on the opening value to perform initial opening loading in order to begin the addition of the additives; During the dripping process, the regulating valve is automatically switched between a time-uniform speed mode and a weight deviation compensation mode. The time-uniform speed mode is as follows: the dripping is carried out at a uniform speed according to the target flow rate, which is the ratio of the target total dripping amount to the target dripping time; the weight deviation compensation mode is as follows: the target flow rate is dynamically adjusted based on the real-time deviation between the actual dripping amount and the target total dripping amount and the remaining dripping time, and the adjusted target flow rate is substituted into the quantitative calculation model to correct the opening of the regulating valve and execute the dripping.

[0006] In one embodiment, the quantitative calculation model is obtained through the following steps: The equipment, additives, and operating conditions used are consistent with the actual free-fall dropping process. Set multiple gradient test points for the regulating valve opening from 0 to 100%. The opening interval between any adjacent gradient test points is less than or equal to the preset opening interval value and covers the actual production opening range. Multiple sets of different initial weights are configured for each gradient test point to obtain multiple test conditions. Each test condition includes a gradient test point and an initial weight. The multiple sets of initial weights cover the range of initial weights in actual production. Add the additive under each test condition, and after the dropping process has been running stably for a preset time, collect the actual stable flow rate under the current opening and the current initial weight to form a data record corresponding to "initial weight - opening - flow rate". Based on the collected data, curve fitting was performed to obtain the three-dimensional relationship curve between the initial weight, opening degree and flow rate, and a quantitative calculation model was derived based on the fitted curve.

[0007] In one embodiment, during the dripping process, the regulating valve is controlled by automatically switching between a time-uniform speed mode and a weight deviation compensation mode, including: controlling the regulating valve based on the time-uniform speed mode within a first preset time after the dripping starts; and switching to the weight deviation compensation mode to control the regulating valve if the dripping starts for more than the first preset time.

[0008] In one embodiment, the method further includes: monitoring the actual flow rate of the additive: obtaining the weight of the dropping tank at the start and end times within a sliding window of a preset time length; performing multi-level filtering on the real-time weight signal; and calculating the average flow rate within the sliding window as the actual flow rate of the additive based on the weight difference after multi-level filtering within the sliding window and the preset time length.

[0009] In one embodiment, controlling the operation of the regulating valve includes executing a multi-step timing interlocking control process, the process comprising: Judgment of dropping conditions; Open the path valve and detect the path valve opening feedback signal; Open the bottom valve and detect the bottom valve opening feedback signal; Start the drip pump and check the drip pump operation feedback signal; Adjust the regulating valve to the calculated opening value, load and maintain for a preset time before entering the dripping stage; Real-time monitoring of the dripping status; Determining whether the additives have been emptied; Delay the second preset time; Stop the drip pump and detect the drip pump stop feedback signal; Close the bottom valve and detect the bottom valve closure feedback signal; Close the path valve and detect the path valve closure feedback signal.

[0010] In one embodiment, determining whether the adjuvant has been emptied includes: Different venting thresholds are set according to the target flow rate; when the weight of the real-time dripping tank reaches the venting threshold corresponding to the current target flow rate, the additive is determined to be vented.

[0011] In one embodiment, the method further includes: during the execution of each step of the multi-step time-sequence interlocking control, if no corresponding device feedback signal is received within a third preset time, a corresponding alarm is triggered and the current control process is paused; a preset regulating valve opening protection range is set, and when the opening exceeds the range, the valve is automatically limited and the dripping time is adaptively adjusted; when an emergency termination signal is received, all actuators are immediately shut down and the dripping process is terminated.

[0012] A second aspect of the present invention provides a control device for free-fall type additive dripping, applied to a control system, comprising: The initial parameter acquisition module is used to acquire the target dripping parameters and the initial weight of the dripping tank; the dripping tank is used to store the additives, and a regulating valve is installed on the discharge pipe of the dripping tank; the target dripping parameters include the target total dripping amount and the target dripping time. The regulating valve opening calculation module is used to calculate the opening value of the regulating valve based on the quantitative calculation model preset in the control system, using the target dripping parameters and the initial weight. The quantitative calculation model characterizes the coupling influence of the initial weight and the opening value on the dripping rate. The initial opening loading module is used to control the regulating valve to perform initial opening loading based on the calculated opening value in order to start the addition of the auxiliary agent; The adjustment and control module is used to automatically switch between time uniform speed mode and weight deviation compensation mode during the dripping process to control the operation of the adjustment valve; The time-uniform speed mode is as follows: the dripping is carried out at a uniform speed according to the target flow rate, which is the ratio of the target total dripping amount to the target dripping time; the weight deviation compensation mode is as follows: the target flow rate is dynamically adjusted based on the real-time deviation between the actual dripping amount and the target total dripping amount and the remaining dripping time, and the adjusted target flow rate is substituted into the quantitative calculation model to correct the opening of the regulating valve and execute the dripping.

[0013] A third aspect of the present invention provides a control system for free-fall type additive dripping, comprising: Dropping tank, used for storing additives; The weighing module is used to collect the weight data of the dripping tank in real time; A regulating valve, installed on the discharge pipe of the dripping tank, is used to control the dripping rate of the additives; Path valves, foot valves, and drip pumps are used to control the delivery path of additives; The control module integrates a control device for free-fall additive dripping, similar to the second aspect, and is connected to the weighing module, regulating valve, path valve, bottom valve, and dripping pump.

[0014] A fourth aspect of the present invention provides a chemical production equipment, including a control system for free-fall type additive dripping as described in the third aspect.

[0015] The free-fall additive dripping control method described in the first aspect above fundamentally solves the problems of lag, inaccuracy, and unstable start-up caused by relying on experience or simple feedback adjustment by using a pre-set quantitative calculation model to directly calculate the valve opening based on target parameters and initial weight. This method quantitatively characterizes the nonlinear and time-varying relationship between valve opening, initial weight, and dripping speed, providing a deterministic basis for valve adjustment, thereby achieving precise and rapid control of the dripping process, especially the start-up phase. Simultaneously, the automatic switching between time uniformity and weight deviation compensation modes effectively balances the time controllability of the dripping process with the accuracy of the final dripping volume, further improving the stability and reliability of the control performance. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the specific embodiments or related technologies of this application, the drawings used in the description of the specific embodiments or related technologies will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic flowchart of the control method for free-fall additive dripping provided in the embodiments of this application.

[0018] Figure 2 This is a schematic diagram illustrating the modeling process of the quantitative calculation model provided in the embodiments of this application.

[0019] Figure 3 This is a schematic diagram of the flow rate monitoring process provided in an embodiment of this application.

[0020] Figure 4 This is a schematic diagram illustrating the process of controlling the operation of the regulating valve as provided in an embodiment of this application.

[0021] Figure 5 A schematic diagram of the structure of the free-fall type additive dripping control device provided in the embodiments of this application.

[0022] Figure 6 This is a schematic diagram of the dripping function block provided in an embodiment of this application.

[0023] Figure 7 The process flow diagram of the actual application project provided in the embodiments of this application is shown.

[0024] Figure 8 An example diagram illustrating the real-time operating status of valves during the production process, provided as an embodiment of this application.

[0025] Figure 9 This is an example diagram illustrating the real-time operational status of traffic flow during the production process, provided as an embodiment of this application.

[0026] Figure 10 This is a schematic diagram of adjustable parameters on the control panel provided in an embodiment of this application.

[0027] Figure 11 This is a schematic diagram of a control system for free-fall additive dripping provided in an embodiment of this application.

[0028] Figure 12 This is a schematic diagram of the hardware structure of the electronic device provided in the embodiments of this application. Detailed Implementation

[0029] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0030] In the field of fine chemical process control, to achieve slow and stable dripping of additives, free-fall dripping is typically used in scenarios where pump delivery is not feasible due to material characteristics. Currently, the commonly used approach involves manual adjustment via a regulating valve or simple automatic adjustment based on a programmable logic controller (PLC), coupled with a weighing module for metering. Specifically, this solution allows operators to set the initial opening of the regulating valve based on experience, and during the dripping process, the valve opening is finely adjusted unidirectionally based on the real-time dripping amount fed back from the weighing module or the calculated actual flow rate, or adjusted using a proportional-integral-derivative (PID) algorithm. Its basic working principle utilizes gravity as the driving force, changing the flow resistance by altering the valve opening, thereby affecting the material flow rate, and forming a closed-loop control with weighing feedback. Its widespread application is primarily due to its ability to achieve basic timed and quantitative dripping functions with relatively simple hardware configuration and intuitive operating logic.

[0031] However, when this scheme is applied to fine chemical synthesis processes (such as acrylic emulsion polymerization) with extremely stringent requirements for uniformity of dripping, accuracy of total volume, and process stability, its performance is less than ideal. The contradiction lies in the fact that, in order to optimize its ease of operation and universality, the inherent experience-based setting and lag feedback adjustment logic inevitably compromises the accuracy and response speed of control, and may even lead to excessive deviations in the total dripping volume or runaway reaction temperature. Specifically, in actual production, when the initial weight differs or the liquid level in the tank drops during dripping, causing changes in gravity-driven pressure, the initial opening set by the operator is often inaccurate due to a lack of understanding of the quantitative relationship between valve opening, initial weight, and dripping rate. This results in excessive deviations between the flow rate and the target value during the start-up phase. Furthermore, subsequent feedback adjustments based on flow rate deviations exhibit significant adjustment lag due to the nonlinearity and time-varying nature of the opening-flow rate relationship, making it difficult to quickly smooth out flow rate fluctuations.

[0032] To overcome the aforementioned contradictions, this invention proposes a different technical approach. Its core concept lies in improving the critical bottleneck of initial valve opening setting and dynamic adjustment by pre-setting a quantitative calculation model characterizing the coupled influence between initial weight, valve opening, and dripping velocity. This effectively enhances the starting accuracy, adjustment response speed, and final total quantity control precision of the dripping process without significantly sacrificing system reliability and applicability. In other words, it provides a control method based on a combination of quantitative model feedforward and multi-mode feedback to solve the problem of control lag and insufficient precision caused by the lack of quantitative characterization of the opening-flow rate relationship in free-fall dripping, achieving stable, accurate, and automated dripping control under complex operating conditions.

[0033] Exemplary Implementation Environment To concretize the inventive concept, a typical implementation environment is described. The free-fall additive dripping control system according to an embodiment of the present invention includes a dripping tank for storing additives, a regulating valve installed on the discharge pipeline of the dripping tank, a weighing module for real-time acquisition of weight data from the dripping tank, and a path valve and a bottom valve for controlling the additive delivery path. Each device is connected to the control module via signal lines. The control module receives the weight signal from the weighing module and sends control commands to the regulating valve, path valve, bottom valve, and optionally the dripping pump. Simultaneously, it can receive start, stop, and other command signals from a higher-level monitoring system or the operator. This system constitutes the physical basis for implementing subsequent control methods.

[0034] Exemplary methods Figure 1 The diagram shown is a schematic flowchart of a free-fall additive dripping control method according to an embodiment of the present invention. The method can be executed by a control module (such as a processor in a DCS) in the aforementioned control system, and includes the following steps: S101, obtain the target dripping parameters and the initial weight of the dripping tank; the dripping tank is used to store the additive, and a regulating valve is installed on the discharge pipe of the dripping tank. The target dripping parameters include the target total dripping amount and the target dripping time.

[0035] Specifically, the initial weight refers to the stable weight value of the dropper containing the additive to be added before the formal start of the dropping process, which is obtained in real time through a weighing module. In some embodiments, the initial weight can be obtained after the dropping start command is confirmed and before any valve opening action is performed; the weighing reading recorded at this time can be used as the initial weight IV. The target dropping parameters, including the target total dropping volume SP and the target dropping time TSP, are set according to actual process requirements. This step provides a clear process objective (SP, TSP) and the current initial state (IV) of the system for the entire control process, serving as the basis for all subsequent calculations and decisions.

[0036] S102, based on the quantitative calculation model pre-installed in the control system, using the target dripping parameters and initial weight, calculate the opening value CV of the regulating valve. SP The quantitative calculation model characterizes the initial weight IV and the valve opening CV. SP The coupling effect between the droplet rate and the droplet speed.

[0037] Specifically, "pre-set" means that the model has been stored in the control system's memory through debugging, training, or configuration before the control system is put into operation, and can be called upon by the control logic at any time. As a specific implementation, this quantitative calculation model can be a double square root coupled formula. For example, the formula can be expressed as: Where SP / TSP is the target flow rate. SP WE SP For reference weight, CO SP Basic opening coefficient, S SP K is the flow rate correction factor. SP This is the working condition correction factor.

[0038] The coefficients in the formula can be determined through preliminary debugging based on specific equipment characteristics, additive properties, and process conditions. This formula clearly shows the opening degree CV. SP Simultaneously, the target flow rate is FLOW. SP The function of (determined by SP and TSP) and the initial weight IV is non-linear (including square root operations). This approach allows for a direct and quantitative mapping of target requirements and system states to control commands for the actuators, overcoming the blindness of empirical settings.

[0039] Quantitative calculation models can be implemented in various ways. For example, they can include, but are not limited to, piecewise linear fitting formulas, high-order polynomial fitting formulas, or neural network models trained with experimental data. These models can all output a predicted valve opening value based on the input target dripping velocity (or SP, TSP) and initial weight IV. Specific means of implementing the above-mentioned "calculate valve opening value" function can include: at the software level, the controller can call a function module containing a preset formula and substitute real-time parameters for calculation; at the hardware level, the calculation logic can also be embedded in a dedicated computing chip (such as an FPGA) to achieve high-speed response.

[0040] S103, based on the calculated opening value CV SP The control valve is opened to the initial degree to begin the addition of the additives.

[0041] This step will use the CV calculated in step S102. SP The value is output as an instruction to the actuator of the control valve (such as an electric valve positioner), causing the control valve to move from the closed or a certain initial position to the CV position. SP The corresponding opening degree. The loading process can be completed instantaneously or slowly ramped to the target value to avoid shock. In some embodiments, to stabilize the opening degree, loading is performed on the CV... SP Then, this opening can be maintained for a short, preset duration Tm. SP（ For example, after 2-5 seconds, once the flow rate has stabilized initially, the dripping stage officially begins. This marks the transition of the dripping process from the feedforward model calculation stage to the actual operation and closed-loop monitoring stage.

[0042] S104, during the dripping process, the regulating valve is automatically switched between a time-uniform speed mode and a weight deviation compensation mode. The time-uniform speed mode is: the flow rate is set at the target flow rate. SP Uniform dripping is used, with the target flow rate being the ratio of the target total dripping volume SP to the target dripping time TSP. The weight deviation compensation mode is based on the real-time deviation DAT between the actual dripping volume FB and the target total dripping volume SP. FB The target flow rate is dynamically adjusted based on the remaining dripping time. The adjusted target flow rate is then substituted into the quantitative calculation model to correct the valve opening and execute the dripping. It should be noted that "automatic switching" in this application does not refer to switching back and forth between two modes, but rather to switching from one mode (uniform time) to another mode (weight deviation compensation) according to the progress of the process, and may continue to make dynamic adjustments in the compensation mode until the dripping ends.

[0043] As a specific implementation method, the preset switching condition can be a time threshold. For example, within the first preset time (e.g., 60 minutes) after the dripping starts, the regulating valve is controlled based on a time-uniform flow mode, i.e., the target flow rate FLOW. SP The SP / TSP ratio is maintained at a constant value, and the valve opening is maintained or finely adjusted using a quantitative calculation model (which may require inverse calculations or table lookups in conjunction with real-time, varying weights). If the dripping start time exceeds the first preset time, the valve is switched to weight deviation compensation mode for control.

[0044] At this point, the actual amount of liquid added (FB) is calculated in real time: FB = IV - PV (PV is the current real-time weight), and the deviation (DAT) is calculated. FB = SP - FB, remaining time = TSP - T1 / 60 (T1 is the dripping time in minutes), then the adjusted target flow rate is FLOW. SP’ =DAT FB / (TSP - T1 / 60). Then FLOW SP’ Substituting into the quantitative calculation model, the new control valve opening CV is calculated. SP’ The system controls the regulating valve to adjust to that opening degree. This process can be performed periodically (e.g., once per second or every few seconds), thereby achieving dynamic compensation based on weight deviation.

[0045] The synergy between S102 and S104 constitutes a perfect combination of feedforward and feedback. S102 provides a precise initial opening based on the model, laying a stable and near-target starting point for the entire dropping process, greatly reducing initial deviations. S104's dual-mode switching strategy balances the uniformity of time control with the final accuracy of the total amount. The stable operation of the time-uniform mode in the early stages contributes to the stability of process parameters; switching to the weight deviation compensation mode later actively corrects any minor deviations that may have accumulated in the early stages, ensuring accurate results. The synergy between these two modes makes the free-fall dropping process both fast and accurate, and stable throughout, thus jointly solving the technical problems of inaccurate control and large fluctuations caused by nonlinear and time-varying coupling relationships.

[0046] To further optimize the accuracy and reliability of the quantitative calculation model in the above embodiments, this application also provides a preferred method for establishing the model. The quantitative calculation model described above can have multiple sources. In a preferred embodiment, such as... Figure 2 As shown, the quantitative calculation model is obtained through a systematic debugging and modeling process, which provides a clear and repeatable technical path for model establishment and ensures a high degree of consistency between the model and the real physical process. In this preferred embodiment, the modeling steps for obtaining the quantitative calculation model are specifically limited to gradient testing and data fitting. This limitation aims to capture the real input-output characteristics of the free-fall dropping system through rigorous experimental design, avoiding subjective assumptions.

[0047] Specifically, it includes the following steps: S201 requires the use of equipment, additives, and operating conditions consistent with the actual free-fall dripping process. This means that the type of regulating valve, pipe size, type of additive (such as a specific emulsifier), ambient temperature, and even the pressure of the dripping tank (if closed) used in the test should be kept as consistent as possible with the actual production environment to ensure the direct applicability of the obtained data.

[0048] S202 sets multiple gradient test points for the control valve opening in the range of 0-100%. The opening interval between any adjacent gradient test points is less than or equal to the preset opening interval value (e.g., 5%), and all test points need to cover the commonly used opening range in actual production (e.g., 10%-80%). The purpose of this design is to obtain sufficiently dense data points in the critical working area to accurately depict the relationship curve between opening and flow rate.

[0049] S203 configures multiple different initial weights for each gradient test point to obtain multiple test conditions. Each test condition includes a gradient test point and an initial weight. The multiple initial weights cover the range of initial weights in actual production.

[0050] Specifically, the configured initial weights should cover the range of initial weights used in actual production (e.g., from half-full to full). At each opening degree, 3-5 different initial weights should be set (covering the commonly used initial weight range in actual production). For example, for a 50% opening test point, tests can be conducted with the additive loaded at 30%, 50%, 70%, and 90% of its rated capacity in the dropping tank. This expands the univariate opening-flow rate test into a comprehensive bivariate (opening degree, initial weight) test.

[0051] S204. Under each test condition, the additive is added dropwise, and after the dropwise process has been running stably for a preset time, the actual stable flow rate under the current opening degree and the current initial weight is collected to form a data record corresponding to "initial weight - opening degree - flow rate".

[0052] Specifically, after the dropping process has been running stably for a preset time (e.g., no less than 30 minutes), the actual stable flow rate at the current opening and the current initial weight is collected. The emphasis here on collecting data "after stable operation" is to eliminate startup transients and accidental interference, and to obtain data representing the steady-state characteristics of the system under this operating condition. Each collection forms a data record corresponding to "initial weight - opening - flow rate".

[0053] S205. Based on the collected data, curve fitting is performed to obtain the three-dimensional relationship curve between the initial weight, opening degree and flow rate, and a quantitative calculation model is derived based on the fitted curve.

[0054] Specifically, a quantitative calculation model describing this relationship is derived based on the fitted surface, such as the aforementioned double square root coupling formula. The fitting accuracy of the formula is verified to ensure that the deviation between the calculated value and the actual value is within the allowable range of the process (deviation ≤ 5%). Through this systematic experimentation and fitting, the obtained model is no longer a black box or purely empirical, but an approximation of the real physical relationship based on a large amount of measured data, and has a high degree of confidence.

[0055] By employing the specific modeling steps described above, this preferred solution provides a robust and reliable quantitative calculation model for the control core. This further helps to solve the problems of unclear model sources and unreliable accuracy, thereby synergistically strengthening the overall technical effect of the core inventive concept of model-based precise feedforward control. Furthermore, the mathematical methods for curve fitting are not limited to the least squares method, but may also include regression analysis, spline interpolation, etc. The interval of gradient test points is not limited to 5%, and can be adjusted between 1% and 10% depending on the required accuracy. Those skilled in the art can easily combine the rigorous modeling method in this embodiment with the dual-mode control flow in the aforementioned embodiments; this combination can simultaneously achieve a high-precision model foundation and intelligent process control effects.

[0056] To further optimize the smoothness of mode switching during the dripping process, this application also provides a preferred scheme regarding the switching conditions. In a preferred embodiment, the preset switching condition is specified as a time threshold.

[0057] In a preferred embodiment, the switching control is specifically defined as using a time-uniform flow rate mode for the first preset time after the dripping starts, and switching to a weight deviation compensation mode after this time. This design provides a clear boundary for the control strategy on the timeline. The principle is that in the initial stage of dripping, the system state (such as pipe fullness and flow stability) is being established. Using a constant target flow rate is beneficial for quickly establishing a stable dripping process, and because the time is short at this stage, the accumulated deviation is usually very small, prioritizing ensuring that the time progress meets expectations. When the dripping has progressed to a certain stage (the first preset time), the system has entered a stable state. At this point, introducing weight deviation-based compensation can most effectively correct any minor deviations that may have occurred in the early stages, ensuring the accuracy of the final total amount.

[0058] Specifically, referring to the aforementioned method description, the first preset time can be set to 60 minutes. When the time recorded by timer T1 in the system is less than 60 minutes, the control module always uses FLOW. SP = SP / TSP is used as a constant value as the target. When T1 is greater than or equal to 60 minutes, and the total dripping time TSP (in hours) multiplied by 60 is greater than T1 (i.e., ensuring there is still time remaining), the control module switches logic and begins to calculate the real-time deviation DAT. FB And the remaining time, and update the FLOW dynamically accordingly. SP The aforementioned first preset time of 60 minutes is merely an example. Those skilled in the art can adjust it according to the total dripping time of different processes, for example, setting it to 1 / 3 or 1 / 2 of the total target time. By adopting the explicit switching logic based on the time threshold described above, this preferred solution can achieve automatic and smooth transition of the control strategy, avoiding disturbances that may be caused by frequent or irregular mode switching. This further helps to solve the problem of how to coordinate the priority of time control and total quantity control, thereby optimizing the overall performance of the dripping process. In addition, the switching condition is not limited to absolute time, but can also be considered as relative time (such as a certain percentage of the target time being reached), or combined with the weight consumption percentage for judgment.

[0059] To obtain a stable and reliable actual flow rate feedback signal during the dripping process to support status monitoring, mode switching, or auxiliary verification, in a preferred embodiment, the method further includes a step of monitoring the actual additive flow rate. This step employs a robust algorithm combining a sliding window and filtering. In this preferred embodiment, flow rate monitoring is specifically defined as including three sub-steps: obtaining the sliding window weight difference, performing multi-stage filtering, and calculating the average flow rate. This effectively filters out high-frequency noise and random interference in the weighing signal, obtaining a velocity value that truly reflects the average flow condition over a period of time. The specific process is as follows: Figure 3 As shown: S301, Obtain the weight of the dropping tank at the start and end times within a sliding window of a preset time length.

[0060] Specifically, the preset time length can be, for example, 30 seconds. The control system maintains a timer T3, which increments at a fixed period (e.g., 0.5 seconds). When T3 is less than a small value (e.g., 0.8 seconds), the current weight PV is recorded as the starting weight PV1 of the window. When T3 reaches 30 seconds, the current weight PV is recorded as the ending weight PV2 of the window, then T3 is reset to zero, and the timing for the next window begins. In this way, a pair of weight values ​​(PV1, PV2) can be obtained every 30 seconds.

[0061] S302 performs multi-stage filtering on the real-time weight signal PV. This can be done before or after calculating the weight difference within the calculation window.

[0062] For example, the original PV signal is first smoothed using a moving average filter module. Then, it may pass through a signal smoothing module to further filter out glitches. Finally, a deviation correction module may be used to handle certain system errors. The weight signal after multi-stage filtering is smoother and more reliable.

[0063] S303, the average flow rate within the sliding window is calculated as the actual additive flow rate Spd based on the weight difference after multi-stage filtering within the sliding window and the preset time length.

[0064] Specifically, the calculation formula is: Spd = ABS(PV1 - PV2) / 30, with units of kg / s; or, Spd = ABS(PV1 - PV2). 2. At this point, the unit is converted to kg / min (because 30 seconds is 0.5 minutes). Using the above monitoring method, through averaging over a fixed time window (e.g., 30 seconds), short-cycle weighing fluctuations and noise can be naturally filtered out. The resulting flow rate value Spd reflects the average flow rate over the past half minute, is very stable, and suitable for process monitoring and trend analysis. This can be achieved through multi-level filtering of the real-time weighing signal using the built-in filtering modules FILTER02, FOD1, and DEV01 in the DCS system. FILTER02 uses a moving average filter with 10 sampling periods, FOD1 is used for signal smoothing, and DEV01 is used for deviation correction, eliminating weighing fluctuation interference from free-falling dripping and improving the stability and accuracy of flow rate monitoring.

[0065] By employing the aforementioned flow velocity monitoring method combining sliding window and multi-stage filtering, this preferred scheme can provide high-quality process feedback variables for the control system. This further helps to solve the problem of unreliable velocity feedback caused by high noise in the weighing signal, which in turn affects monitoring and decision-making, thereby improving the robustness of the entire control system. Furthermore, the length of the sliding window is not limited to 30 seconds and can be adjusted between 10 and 120 seconds depending on the signal noise level and control response requirements. The number of filtering stages and the specific algorithm can also have various variations.

[0066] To ensure the automation, safety, and reliability of the dripping process and achieve unattended operation from start to finish, this application also provides a preferred control scheme including specific timing interlocks. In a preferred embodiment, the process of controlling the regulating valve's action is specified as executing a multi-step timing interlock control process. Controlling the regulating valve's action includes executing a multi-step timing interlock control process, which sequentially includes: Num=0: Judgment of the dripping condition; Num=1: Open the path valve and detect the path valve opening feedback signal; Num=2: Open the bottom valve and detect the bottom valve opening feedback signal; Num=3: Start the drip pump and check the drip pump operation feedback signal; Num4: Adjust the regulating valve to the calculated opening value, load and maintain for the preset time before entering the dripping stage; Num=5: Real-time monitoring of the dripping status; Num=6: Determining whether the adjuvant has been emptied; Num=7: Delay the second preset time; Num=8: Stop the drip pump and detect the drip pump stop feedback signal; Num=9: Close the bottom valve and detect the bottom valve closing feedback signal; Num=10: Close the path valve and detect the path valve closure feedback signal.

[0067] To further improve the safety and fault tolerance of the control system and cope with possible on-site equipment failures, communication timeouts or emergency situations, the present application further provides a preferred solution for abnormal handling and safety interlocking. In a preferred embodiment, the method further comprises a plurality of additional safety protection measures. These measures are intended to construct a multi-level safety protection network. In this preferred solution, these safety features mainly include timeout alarm and process suspension, opening limit protection for regulating valves, and emergency shutdown interlocking.

[0068] Specifically, first, during the execution of each step of the multi-step sequential interlocking control, if a corresponding equipment feedback signal is not received within a third preset time (e.g., 60 seconds), a corresponding alarm is triggered and the current control process is suspended. For example, in the step of opening a path valve, timing starts after an opening command is issued. If the "opened" feedback is not received within 60 seconds, the system triggers corresponding alarm information MSG (for example, alarm codes 14001-14018) when an abnormality occurs, and stops at the current step to wait for inspection and intervention by an operator, so as to prevent process deadlock or subsequent misoperation caused by valve jamming and other reasons.

[0069] Secondly, a regulating valve opening protection interval [Kmin, Kmax] is preset. After calculating the opening CV based on the quantitative calculation model SP , comparison is performed: if CV SP < Kmin, Kmin is forcibly output; if CV SP > Kmax, Kmax is forcibly output. The setting of Kmin (for example, 5%) is to prevent the opening from being too small, which would cause the valve to approach the dead zone, resulting in unstable or zero flow; the setting of Kmax (for example, 95%) is to prevent flow velocity out of control caused by excessive opening. When the opening is limited, the system can also adaptively adjust the expected dropping time or send out a prompt, because the actual flow velocity will deviate from the value calculated by the original model. Finally, when the control system receives an emergency shutdown signal (such as the F1 signal triggered by an operator on the HMI), it immediately closes all actuators (resets the regulating valve to zero, stops the pump, closes the bottom valve and path valve) and terminates the dropping process.

[0070] By adopting the above comprehensive abnormal handling and safety interlocking mechanism, the preferred solution can significantly improve the robustness and safety of the free-fall dropping control system when facing abnormal working conditions. This further helps to solve secondary problems that may be caused by equipment failures or urgent manual shutdowns in the automated process, thereby ensuring the safety of personnel, equipment and the production environment. It can be understood by those skilled in the art that the specific values of the third preset time and the opening protection interval can be flexibly set according to equipment performance and safety specifications.

[0071] In one example, controlling the action of the regulating valve involves executing a multi-step time-sequenced interlocking control process. This process aims to ensure that each actuator starts and stops in the correct sequence through standardized steps and rigorous equipment status verification, preventing misoperation and equipment damage. The execution status is confirmed through valve feedback signals V1_INFO and V2_INFO, and pump operation feedback signal P_INFO. In this preferred embodiment, the process sequentially includes more than ten key steps, forming a complete automated closed loop. Specifically: Num=0: Dropping condition judgment. The control system checks whether the dropping path selection signal DES is valid and whether the process-permitted dropping condition signal Pmt is true. If any condition is not met, the corresponding alarm is triggered and the process is suspended.

[0072] Once the conditions are met, the system enters Num=1: the path valve is opened, and the path valve opening feedback signal V1_INFO is detected. The control system issues the V1_CTL=TRUE command and starts a timeout. If V1_INFO=TRUE is received within the third preset time (e.g., 60 seconds), the opening is confirmed to be successful, and the system proceeds to the next step; otherwise, an alarm is triggered.

[0073] Num=2: Open the bottom valve and detect the bottom valve opening feedback signal V2_INFO. If no feedback is received within the time limit, an alarm will be triggered.

[0074] Num=3: Start the drip pump (if configured), detect the drip pump operation feedback signal P_INFO or the no-pump signal P_NC, issue the P_CTL=TRUE command, wait for feedback, and alarm if timeout occurs.

[0075] Num=4: Adjust the regulating valve to the calculated opening value CV_SP, load and maintain it for a preset time Tm_SP before entering the dripping stage. This step performs the aforementioned initial opening loading and provides a short stabilization period.

[0076] Num=5: Real-time monitoring of the dripping status. This step is the core stage of the dripping process, during which dual-mode control logic and flow rate monitoring are executed.

[0077] Num=6: Determine if the adjuvant has been purged. If the purging condition is met, proceed to the next step.

[0078] Num=7: Delay the second preset time TSP1. This delay is to allow the remaining additives in the pipeline to continue dripping under gravity, ensuring the accuracy of the total amount.

[0079] Num=8: Stop the drip pump and check the drip pump stop feedback signal. Issue the P_CTL=FALSE command and wait for feedback confirmation. If no feedback is received within the time limit, an alarm will be triggered.

[0080] Num=9: Close the foot valve and detect the foot valve closure feedback signal. Issue the V2_CTL=FALSE command and wait for feedback confirmation. If no feedback is received within the timeout period, an alarm will be triggered.

[0081] Num=10: Close the path valve and detect the path valve closure feedback signal. Issue the V1_CTL=FALSE command and wait for feedback confirmation. If no feedback is received within the time limit, an alarm will be triggered, and the dripping process will be completely completed.

[0082] By employing the aforementioned multi-step timing interlocking control, which incorporates rigorous feedback detection and sequential logic, this preferred solution achieves a high degree of automation and safety assurance in the dripping process. The detection feedback signal at each step ensures that the mechanical actions are executed correctly. This further helps to address safety hazards caused by human error and unclear equipment status, thereby improving the reliability and safety of production operations. Furthermore, the number and order of timing steps can be increased, decreased, or adjusted according to the specific process; for example, in systems without a dripping pump, certain steps can be omitted.

[0083] To accurately determine whether the additive has been emptied at the end of the dripping process and avoid misjudgment or total quantity deviation due to pipeline residue or weighing errors, this application also provides a preferred scheme for emptying determination. As mentioned in the above process, there is a "determination of whether the additive has been emptied" step. In a preferred embodiment, this determination logic is specifically optimized to set thresholds based on the target flow rate. In this preferred scheme, the emptying determination includes: determining the threshold based on the target flow rate. SP Different purging thresholds are set according to the size of the dripping tank. When the real-time weight (PV) of the dripping tank reaches the purging threshold corresponding to the current target flow rate, the additive is determined to be purged. The principle behind this design is that the dynamic error of the weighing system, the amount of residual material in the pipeline, and the urgency of the judgment vary at different dripping speeds. At low dripping speeds, the residual weight is small, requiring a more sensitive threshold; at high dripping speeds, a slightly larger threshold is allowed to avoid false triggering due to noise. Specifically, the grading settings can be as follows: 1. When the target flow rate is FLOW SP When the value is less than 25, the condition for emptying is PV ≤ W. SP + 0.4, where W SP = IV - SP is the target remaining weight (that is, the weight that should theoretically remain in the can after the dripping is completed).

[0084] 2. When 25 ≤ FLOW SP When <100, the condition is PV≤W SP +FLOW SP / 25.

[0085] 3. When FLOW SP When the flow rate is ≥100 kg / min, the condition is that PV ≤ W. SP +4.

[0086] 4. When PV≤0.001 and W SP When the value is ≤0.001, it is directly determined as a drop empty.

[0087] This tiered threshold method allows the venting judgment to adapt to different process stages (because of FLOW). SP (It changes dynamically in weight deviation compensation mode), making it more intelligent and accurate.

[0088] By employing the aforementioned emptying judgment logic based on target flow rate grading, this preferred scheme can make a more accurate determination of the termination timing at the end of the dripping process. This further helps to solve the problem that the traditional fixed threshold method is prone to premature or late termination of dripping in variable flow rate scenarios, thereby ensuring high accuracy of the final total dripping volume and reliability of process termination. In addition, the constants in the threshold formula (0.4, 25, 4, etc.) can be calibrated and adjusted according to the actual weighing system accuracy and additive characteristics.

[0089] Furthermore, this embodiment of the invention sets up a dropping end determination logic: when any of the following process conditions are met, such as dropping time reaching TSP, real-time dropping amount W reaching SP, or dropping tank being empty, the dropping end procedure is triggered, the opening of the regulating valve is adjusted to 0, and the dropping is completed.

[0090] Based on the control logic of the above-described free-fall additive dripping control method embodiment, a complete flowchart is shown in a practical application example, as follows: Figure 4 As shown: S1 process start-up: The start command is issued through the Batch (batch management system) or DCS operation interface. At the same time, process parameters such as the target total amount of dripping and the target dripping time are set in the interface to complete the parameter configuration of the dripping task and trigger the start of the dripping control process.

[0091] S2 pipeline valve opening: The control system issues a command to sequentially open all valves such as the path valve and bottom valve of the dripping pipeline to complete the material conveying link. During the valve opening process, the full opening feedback signal of each valve is detected simultaneously. If the corresponding feedback signal is not received within the preset third preset time (60S), the corresponding alarm is triggered and the current control process is paused to ensure that the pipeline is fully connected before entering the next stage.

[0092] S3 Regulating Valve Initial Opening Loading: Based on the quantitative calculation model pre-installed in the control system, combined with the initial weight of the dripping tank and the target dripping parameters, the initial opening value of the regulating valve is calculated, and the regulating valve is controlled to perform initial opening loading. After loading is completed, the initial dripping flow rate is obtained, where the initial flow rate is calculated through the quantitative calculation model (characterizing the coupling influence relationship between the initial weight, the regulating valve opening and the dripping speed). This stage is maintained for 30 seconds (which can be adjusted according to process requirements) to stabilize the system and lay the foundation for subsequent precise control.

[0093] S4 Flow Rate Climbing Adjustment: The climbing adjustment logic slowly adjusts the opening of the regulating valve to smoothly transition the actual dripping flow rate to the target flow rate (the target flow rate is the ratio of the target dripping total amount to the target dripping time). This climbing phase is maintained for 30 seconds (configurable). During the adjustment process, the average flow rate and the instantaneous flow rate are compared in real time to ensure that the flow rate is stable and without shock. If the flow rate setting changes, the control logic first climbs the regulating valve to near the set flow rate and then performs automatic fine-tuning to avoid flow fluctuations caused by abrupt valve movements.

[0094] S5 regulating valve automatic closed-loop control: After entering the dropping stabilization stage, the control system automatically switches between time uniform speed mode and weight deviation compensation mode to perform closed-loop automatic adjustment of the regulating valve. Within the first preset time (60 seconds) after the dripping starts, a time-uniform speed mode is adopted to drip at a uniform rate according to the target flow rate. After the first preset time is exceeded, the system switches to a weight deviation compensation mode, calculates the real-time deviation between the actual dripping amount and the target total amount, dynamically adjusts the target flow rate based on the real-time deviation and the remaining dripping time, and substitutes the adjusted target flow rate into the quantitative calculation model to correct the opening of the regulating valve to achieve precise dripping. At the same time, the control system monitors parameters such as dripping amount and actual flow rate in real time, judges abnormal dripping conditions (such as pipe blockage, leakage, abnormal weighing, etc.), and triggers the corresponding interlock protection.

[0095] S6 regulating valve closed: When the real-time weight of the dripping tank reaches the venting judgment threshold corresponding to the current target flow rate, and it is determined that the amount of additive added has reached the set total amount, the control system issues a command to close the regulating valve and stop the material conveying; whether the valve needs to be closed in advance can be set according to the actual process conditions to adapt to the venting requirements of different materials.

[0096] S7 pipeline switch valve closure: After the regulating valve is fully closed, the control system sequentially closes all switch valves such as the path valve and foot valve of the drip pipeline to cut off the material conveying path; it also simultaneously detects the full closure feedback signal of each valve to ensure that the pipeline is completely cut off and to avoid material leakage.

[0097] S8 Control Parameter Reset: After the dripping process is completed, the control system automatically resets all relevant parameters, including cumulative dripping amount, valve status, alarm information, control mode, etc., clears the process data of this dripping, and prepares for the next batch of dripping tasks.

[0098] S9 process ends: After all steps are completed and parameters are reset, the dripping control process ends, the system returns to standby mode, and waits for the next start command.

[0099] Since the control method provided in this application is based on the principle of weighing reduction, it achieves precise flow rate control of free-fall dripping through regulating valves. For applications involving simultaneous dripping of multiple tanks, a synchronization judgment function block can be added before this function block to achieve synchronous interlocking control of multi-flow-path dripping and avoid mutual interference between multiple tanks. At the same time, the system presets a regulating valve opening protection range. When the calculated opening exceeds the range, it automatically limits the valve and adaptively adjusts the dripping time. When an emergency termination signal is received, it immediately shuts down all actuators and terminates the dripping process to ensure production safety.

[0100] The method provided in this application, by establishing a quantitative calculation model of opening-flow velocity specifically for free-fall scenarios and integrating time-weight dual-mode control logic, accurately solves the core defects of existing technologies and achieves the following technical effects, all of which have been verified through actual process testing: 1. Improved accuracy of valve opening setting: The initial valve opening is automatically calculated by a double square root coupling formula, replacing empirical setting, and completely eliminating problems such as flow rate runaway and flow rate of 0 caused by the initial opening being too large or too small. Tests show that the deviation between the initial flow rate and the target flow rate is ≤3%, which is far better than the deviation of more than 10% of the traditional empirical setting, and the stability of dripping start-up is significantly improved.

[0101] 2. Improved adjustment response speed and accuracy: Based on the formula, the system achieves active prediction and adjustment of the flow rate target to the valve opening. Combined with dual-mode switching control, it replaces the traditional passive compensation for deviation. The adjustment lag time is shortened from the traditional 5-10s to 1-2s. The flow rate fluctuation range is controlled within ±5% of the process allowable value, and the uniformity of dripping is significantly improved. The 30-second sliding window flow rate monitoring and multi-level filtering effectively eliminate weighing fluctuation interference, and the flow rate monitoring accuracy is improved by more than 60%.

[0102] 3. Enhanced stability of dripping control: To address issues such as gravity changes and additive adhesion in free-fall scenarios, the flow rate fluctuation can be quickly corrected by adapting the quantitative formula to the nonlinear relationship between the opening and the flow rate, combined with a weight deviation compensation mode. Tests show that in the acrylic emulsion polymerization process, the reaction temperature fluctuation throughout the dripping process is ≤2℃, which is far superior to the fluctuation of more than 5℃ in traditional control, avoiding production alarms and interlocking reactions caused by abnormal temperatures; the accuracy of the total dripping volume can be improved to within ±0.4kg, meeting the requirements for high-precision dripping.

[0103] 4. Enhance automation and centralization: Through 11-step full-process time-sequence interlocking control, the entire process from opening the path valve to the end of dripping is fully automated, eliminating the need for manual on-site supervision and intervention. Each step includes timeout alarms and equipment feedback confirmation, reducing misoperation and safety hazards, and increasing production efficiency by more than 30%.

[0104] 5. Consideration of process adaptability: The coefficients of the double square root coupling formula can be readjusted according to experimental data of different additives and different working conditions to adapt to various fine chemical processes that require free fall drop addition.

[0105] Exemplary devices and systems To enable the inventive concept to be easily integrated into existing distributed control systems (DCS) in a modular software form, this application also provides an embodiment of a control device. This device is applied to a control system and is essentially a modular implementation of the functions described in the foregoing method embodiment. Figure 5 The diagram shown is a schematic block diagram of a free-fall type additive dripping control device according to an embodiment of the present invention. The device includes an initial parameter acquisition module 501, a regulating valve opening calculation module 502, an initial opening loading module 503, and a regulating control module 504.

[0106] The initial parameter acquisition module 501 is used to acquire the target dripping parameters and the initial weight IV of the dripping tank. The regulating valve opening calculation module 502 is used to calculate the regulating valve opening value CV based on the quantitative calculation model preset in the control system, using the target dripping parameters and the initial weight IV. SP This module has pre-stored or can call up quantitative calculation models.

[0107] The initial opening loading module 503 is used to load the opening value CV based on the calculated opening value. SP The control valve is opened to the initial degree to begin the addition of the additives.

[0108] The adjustment and control module 504 is used to automatically switch between time uniform speed mode and weight deviation compensation mode during the dripping process to control the operation of the adjustment valve.

[0109] The modules communicate with each other via data bus or software interface, working collaboratively to achieve a complete control flow. This device can exist as a software function block (such as a user-defined function block (FB) in a DCS), an application-specific integrated circuit (ASIC), or processor-executable program code. For example... Figure 6The diagram shows a function block named DROPP_R1002A (DROPP for short), a custom control function block specifically developed for free-fall additive dispensing. It encapsulates core algorithms such as a quantitative calculation model, dual-mode switching between time uniformity and weight deviation compensation, and multi-step timing interlock control. Left side: Input interface (IN): Receives external signals such as setpoints, field feedback, and control commands. Right side: Output interface (OUT): Outputs control results, status, alarms, and other signals to the DCS screen, other function blocks, and actuators. Pink lines: Internal parameters / reserved interfaces used for internal logic, debugging, or expansion of the function block.

[0110] The functional blocks in this embodiment of the invention also include a data interaction module, used for data interaction with the central control room of the DCS system, field sensors (weighing modules), and actuators (regulating valves, valves, pumps), supporting parameter configuration, data acquisition, real-time monitoring, and historical data traceability. Figure 7 The diagram shown is a process flow chart for a real-world application project, such as... Figure 8 The image shows the real-time operating status of valves during the production process, and Figure 9 The diagram shown is an example of the real-time operation status of the flow during the monitoring of the production process.

[0111] The above functional blocks are written in ST structured control language, can be reused in DCS systems, support parameter configuration adjustment, and are adaptable to different specifications of free-fall dripping equipment and process requirements. "Opening-flow rate formula parameters," "Target flow rate-target opening conversion," and "Real-time flow rate trend" display windows are added to the HMI process flow diagram to facilitate operator monitoring and parameter fine-tuning. At the same time, auxiliary adjustment parameters are added to the control panel to adapt to minor changes in on-site operating conditions, such as... Figure 10 The diagrams (A)-(C) in the diagram show the adjustable parameters on the control panel.

[0112] The apparatus provided in this application embodiment can be used to execute the technical solutions of the above method embodiments. Its implementation principle and technical effect are similar, and will not be repeated here.

[0113] Furthermore, each module in the aforementioned device can be implemented as a more refined sub-module. For example, the adjustment and control module 504 may include a mode switching sub-module, a target flow rate calculation sub-module, and a deviation calculation sub-module. The initial parameter acquisition module 501 may include a signal filtering sub-module for preprocessing the acquired initial weight IV. The specific implementation methods of all these modules, including their internal algorithms, logical judgments, parameter storage, etc., can be referred to the detailed description in the foregoing method embodiments. Encapsulating the control logic into such a device or functional block greatly facilitates the configuration, reuse, and maintenance in DCS engineering, realizing the software-based encapsulation of control knowledge.

[0114] By integrating the aforementioned DCS functional blocks into the existing DCS system, centralized data acquisition, real-time monitoring, and historical data traceability are achieved, which meets the development needs of the process industry for "decentralized control and centralized operation." The functional blocks are based on secondary development of the existing DCS system, which does not require large-scale hardware modifications, resulting in low modification costs. Furthermore, the parameter display and fine-tuning functions of the HMI panel retain the space for operator intervention, which is in line with on-site operating habits. The functional blocks can be reused, reducing the development costs and time of subsequent projects.

[0115] Meanwhile, considering the issues of regulating the flow rate, weighing and reducing the volume, controlling free fall, and synchronous dripping, a synchronous judgment function block is added before this function block. This ensures that the dripping is timed and quantitative while maintaining synchronization. Through precise conversion between target flow rate and target opening and auxiliary compensation for the dripping amount, the timed and quantitative dripping of a single additive is ensured. At the same time, multiple additives can calculate their target opening separately through their respective DCS function blocks to achieve synchronous and uniform dripping. Tests show that the synchronous dripping error of multiple additives is ≤1%, which meets the synchronous dripping requirements of processes such as acrylic emulsion polymerization.

[0116] Based on the above method or apparatus, this application also provides a complete embodiment of a control system. For example... Figure 11 As shown, a control system for free-fall additive dripping includes a dripping tank 1101, a weighing module 1102, a regulating valve 1103, a path valve 1104, a bottom valve 1105, a dripping pump 1106, and a control module 1107. The dripping tank 1101 stores the additive, and the weighing module 1102 collects the weight data PV of the dripping tank in real time. The regulating valve 1103 controls the dripping speed of the additive. The path valve 1104, bottom valve 1105, and dripping pump 1106 control the delivery path of the additive. The control module 1107 integrates the control device for free-fall additive dripping as described above, and the weighing module 1102, regulating valve 1103, path valve 1104, bottom valve 1105, dripping pump 1106, and control module 1107 are signal-connected. The control module can be an industrial controller (such as a PLC), a control station of a DCS, or an industrial computer, which runs a program or function block that implements the control logic of this invention. The system constitutes a complete physical entity capable of precise and automated dripping.

[0117] Finally, this application also provides an embodiment of a chemical production equipment. This chemical production equipment, for example, is a reaction production line for acrylic acid emulsion polymerization, which integrates batch production technology with intelligent automated control technology. Its key feature is the inclusion of the aforementioned free-fall additive dropwise control system 1100. This dropwise control system, as a crucial subsystem of the production equipment, is responsible for the precise addition of various additives to the main reactor, thereby ensuring the stable quality of the final chemical product and the high efficiency and safety of the production process.

[0118] Other components of the equipment, such as the reactor, agitator, and temperature and pressure control system, work in conjunction with the dripping control system to form a modern intelligent production unit. This enables fully automated operation from feeding, additive dripping, reaction control to discharge, reducing manual intervention and improving batch stability and production safety. The equipment architecture is easily expandable to other fine chemical polymerization production lines, possessing good versatility and promotional value, providing core equipment support for chemical enterprises to achieve intelligent manufacturing upgrades.

[0119] Exemplary device Figure 12 This is a schematic diagram of the hardware structure of the electronic device provided in an embodiment of this application. Figure 12 As shown, the electronic device of this embodiment includes a processor 1201 and a memory 1202.

[0120] The memory 1202 stores computer execution instructions; the processor 1201 executes the computer execution instructions stored in the memory to implement the various steps performed by the electronic device in the above embodiments. For details, please refer to the relevant descriptions in the foregoing method embodiments.

[0121] Alternatively, the memory 1202 can be either standalone or integrated with the processor 1201.

[0122] When the memory 1202 is set up independently, the electronic device also includes a bus 1203 for connecting the memory 1202 and the processor 1201.

[0123] Exemplary media and products In addition to the methods, apparatus, and devices described above, embodiments of this disclosure can also be computer program products, comprising computer program instructions that, when executed by a processor, cause the processor to perform the various steps of the energy-saving control method for new energy vehicles provided in the various embodiments of this disclosure. The computer program product can be written in any combination of one or more programming languages ​​to perform the operations of the embodiments of this disclosure. Programming languages ​​include object-oriented programming languages ​​such as Java and C++, as well as conventional procedural programming languages ​​such as C or similar languages. The program code can be executed entirely on a user computing device, partially on a user device, as a standalone software package, partially on a user computing device and partially on a remote computing device, or entirely on a remote computing device or server.

[0124] Furthermore, embodiments of this disclosure may also be storage media (e.g., computer-readable storage media) storing a computer program (or instructions) thereon, which, when run by a processor, causes the processor to perform the various steps of the cross-modal retrieval methods for a specific domain provided in the various embodiments of this disclosure.

[0125] The storage medium may be any combination of one or more readable media. A readable medium may be a readable signal medium or a readable storage medium. A readable storage medium may include, for example, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of readable storage media (a non-exhaustive list) include: electrical connections having one or more wires, portable disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof.

[0126] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this disclosure.

[0127] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0128] In the several embodiments provided in this disclosure, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0129] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0130] Furthermore, the functional units in the various embodiments of this disclosure can be integrated into a similar region segmentation unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. If the function is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this disclosure, in essence, or the part that contributes to the prior art, or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods in the various embodiments of this disclosure. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory, random access memory, magnetic disks, or optical disks.

[0131] The above are merely specific embodiments of this disclosure, but the scope of protection of this disclosure is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this disclosure should be included within the scope of protection of this disclosure. Therefore, the scope of protection of this disclosure should be determined by the scope of the claims.

Claims

1. A control method of free-fall type auxiliary agent dropwise addition, characterized by, Applied to a control system, the method includes: Obtain the target dropping parameters and the initial weight of the dropping tank; the dropping tank is used to store the additives, and a regulating valve is installed on the discharge pipe of the dropping tank. The target dropping parameters include the target total dropping volume and the target dropping time. Based on the quantitative calculation model pre-installed in the control system, the opening value of the regulating valve is calculated using the target dripping parameters and the initial weight. The quantitative calculation model characterizes the coupling influence relationship between the initial weight, the opening of the regulating valve, and the dripping speed. The control valve is adjusted based on the opening value to perform initial opening loading in order to begin the addition of the additives; During the dripping process, the regulating valve is automatically switched between a time-uniform speed mode and a weight deviation compensation mode. The time-uniform speed mode is as follows: the dripping is carried out at a uniform speed according to the target flow rate, which is the ratio of the target total dripping amount to the target dripping time; the weight deviation compensation mode is as follows: the target flow rate is dynamically adjusted based on the real-time deviation between the actual dripping amount and the target total dripping amount and the remaining dripping time, and the adjusted target flow rate is substituted into the quantitative calculation model to correct the opening of the regulating valve and execute the dripping.

2. The method according to claim 1, characterized in that, The quantitative calculation model is obtained through the following steps: The equipment, additives, and operating conditions used are consistent with the actual free-fall dropping process. Set multiple gradient test points for the regulating valve opening from 0 to 100%. The opening interval between any adjacent gradient test points is less than or equal to the preset opening interval value and covers the actual production opening range. Multiple sets of different initial weights are configured for each gradient test point to obtain multiple test conditions. Each test condition includes a gradient test point and an initial weight. The multiple sets of initial weights cover the range of initial weights in actual production. Add the additive under each test condition, and after the dropping process has been running stably for a preset time, collect the actual stable flow rate under the current opening and the current initial weight to form a data record corresponding to "initial weight - opening - flow rate". Based on the collected data, curve fitting was performed to obtain the three-dimensional relationship curve between the initial weight, opening degree and flow rate, and a quantitative calculation model was derived based on the fitted curve.

3. The method according to claim 1 or 2, characterized by, During the dripping process, the regulating valve is automatically switched between a time-uniform speed mode and a weight deviation compensation mode, including: Within the first preset time after the dripping start, the regulating valve is controlled based on the time uniform speed mode. If the dripping start time exceeds the first preset time, switch to weight deviation compensation mode to control the regulating valve.

4. The method according to claim 1, characterized in that, Also includes: Monitor the actual flow rate of the additives: Obtain the weight of the dropping container at the start and end times within a sliding window of a preset time length; Perform multi-stage filtering on the real-time weight signal; The average flow rate within the sliding window, calculated based on the weight difference after multi-stage filtering and the preset time length, is used as the actual additive flow rate.

5. The method according to claim 1 or 4, characterized in that, Controlling the operation of the regulating valve involves executing a multi-step time-sequenced interlocking control process, which includes the following steps in sequence: Judgment of dropping conditions; Open the path valve and detect the path valve opening feedback signal; Open the bottom valve and detect the bottom valve opening feedback signal; Start the drip pump and check the drip pump operation feedback signal; Adjust the regulating valve to the calculated opening value, load and maintain for a preset time before entering the dripping stage; Real-time monitoring of the dripping status; Determining whether the auxiliary agents have been emptied; Delay the second preset time; Stop the drip pump and detect the drip pump stop feedback signal; Close the bottom valve and detect the bottom valve closure feedback signal; Close the path valve and detect the path valve closure feedback signal.

6. The method according to claim 5, characterized in that, Determining whether the excipients have been emptied includes: Different evacuation judgment thresholds are set according to the target flow velocity classification; When the weight of the real-time dripping tank reaches the emptying judgment threshold corresponding to the current target flow rate, it is determined that the additive is emptied.

7. The method according to claim 5, characterized in that, Also includes: If no corresponding device feedback signal is received within the third preset time during the execution of each step of the multi-step timing interlocking control, the corresponding alarm will be triggered and the current control process will be suspended. The valve opening protection range is preset, and the valve automatically limits the opening when it exceeds the range and adjusts the dripping time accordingly. Upon receiving an emergency termination signal, immediately shut down all actuators and terminate the dripping process.

8. A control device for free-fall type additive dripping, characterized in that, Applied to a control system, including: The initial parameter acquisition module is used to acquire the target dripping parameters and the initial weight of the dripping tank; the dripping tank is used to store the additives, and a regulating valve is installed on the discharge pipe of the dripping tank; the target dripping parameters include the target total dripping amount and the target dripping time. The regulating valve opening calculation module is used to calculate the opening value of the regulating valve based on the quantitative calculation model preset in the control system, using the target dripping parameters and the initial weight. The quantitative calculation model characterizes the coupling influence of the initial weight and the opening value on the dripping rate. The initial opening loading module is used to control the regulating valve to perform initial opening loading based on the calculated opening value in order to start the addition of the additives; The adjustment and control module is used to automatically switch between time uniform speed mode and weight deviation compensation mode during the dripping process to control the operation of the adjustment valve; The time-uniform speed mode is as follows: the dripping is carried out at a uniform speed according to the target flow rate, which is the ratio of the target total dripping amount to the target dripping time; the weight deviation compensation mode is as follows: the target flow rate is dynamically adjusted based on the real-time deviation between the actual dripping amount and the target total dripping amount and the remaining dripping time, and the adjusted target flow rate is substituted into the quantitative calculation model to correct the opening of the regulating valve and execute the dripping.

9. A control system for free-fall auxiliary agent dosing, characterized by, include: Dropping tank, used for storing additives; The weighing module is used to collect the weight data of the dripping tank in real time; A regulating valve, installed on the discharge pipe of the dripping tank, is used to control the dripping rate of the additives; Path valves, foot valves, and drip pumps are used to control the delivery path of additives; The control module integrates the control device for free-fall additive dripping as described in claim 8, and is connected to the weighing module, regulating valve, path valve, bottom valve and dripping pump.

10. A chemical production plant, characterized by Including the free-fall type additive dripping control system as described in claim 9.

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